Most roads are paved with asphalt, which is produced at an asphalt plant and transported to the construction site in large truck beds such as dump trucks. A difficulty with the transportation operation is that the asphalt tends to stick on contact to any surface. The sticking of the asphalt to the surface of the truck bed prevents the asphalt from smoothly sliding out of the bed as the dump truck attempts to discharge its asphalt load. As a result, workers must coax the asphalt out of the bed using tools and/or environmentally hazardous chemicals. This sticking of the asphalt also affects other storage and transport vehicles such as drums, storage tanks, trailers and piping, as well as tools and other process equipment such as rollers (e.g., rubber-tired and steel-drum rollers), pavers and blades.
Asphalt release agents are known to prevent asphalt from sticking to metallic surfaces. A common release agent used in the past was a hydrocarbon fuel such as ordinary diesel fuel. Such fuels are extremely effective in cutting asphalt to prevent it from sticking. However, the reason for their effectiveness is that they combine with and dilute the asphalt. This impairs the structural integrity of the laid asphalt in the roadway. Also, excessive use of fuel as a release agent contaminates the ground beneath the truck. For these reasons, the Department of Transportation and many state highway departments have severely restricted the use of fuel as a release agent.
Other non-fuel-based asphalt release agents are known to the art. However, most of these other release agents suffer from some combination of being limited in their effectiveness, being environmentally dangerous or expensive. Most of these other release agents also suffer from their complexity in either the delivery, preparation or application steps of utilization. Importantly, existing release agents combine with the asphaltic material and thus are effective for only a single application.
Thus, a need exists for an asphalt release agent which is effective in preventing the sticking of asphalt to truck beds and other surfaces, innocuous and inexpensive, environmentally safe, long-lasting when coated on asphalt-contact surfaces, i.e. does not wash off into the asphaltic material, and does not dilute or otherwise compromise the quality of the asphalt.